Premium
Influence of progesterone and estradiol on cardiovagal baroreflex sensitivity in young healthy women
Author(s) -
Martini Emily R,
Miner Jennifer A,
Brunt Vienna E,
Smith Michael M,
Kaplan Paul F,
Halliwill John R,
Minson Christopher T
Publication year - 2010
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.24.1_supplement.1020.3
Subject(s) - baroreflex , medicine , endocrinology , estrogen , sodium nitroprusside , blood pressure , hormone , phenylephrine , antagonist , heart rate , receptor , nitric oxide
Objective Our goal was to measure cardiovagal baroreflex (CVBR) sensitivity in young healthy women during gonadotropin‐releasing hormone antagonist (GnRHa), progesterone only (GnRHa+P 4 ), estrogen only (GnRha+E 2 ), and combined progesterone plus estrogen (GnRHa+P 4 +E 2 ) conditions. Methods We suppressed endogenous estrogens and P 4 in 31 premenopausal women with GnRHa for 10 days. Subjects were randomized into 2 groups and studied as indicated in figure below. CVBR sensitivity was assessed by lowering and raising blood pressure with intravenous administration of sodium nitroprusside and phenylephrine. CVBR sensitivity was determined as the slope relating R‐R interval and systolic blood pressure. Results No differences in slopes were seen on day 4 (trial 1) and day 10 (trial 3) in Groups 1 or 2. Slopes were significantly higher after P 4 only (17.18 ± 1.28) compared to GnRHa only (14.07 ± 1.17), P 4 +E 2 (14.12 ± 1.23), and E 2 only (12.33 ± 1.21). Estradiol CVBR slopes were significantly lower than GnRHa only and P 4 +E 2. Thus, P 4 only > GnRha only = P 4 + E 2 > E 2 only; all p<0.0001. Conclusions Exogenous sex hormones in young healthy women significantly altered the CVBR slope. P 4 increases and E 2 decreases this slope, and appear to antagonize each other. Supported by NIH Grant HL081671.